Biochemical and genetic characterization of a mutant of Escherichia coli with a temperature-sensitive valyl ribonucleic acid synthetase.
Böck, August (Purdue University, Lafayette, Ind.), Lia Eidlic Faiman, and Frederick C. Neidhardt. Biochemical and genetic characterization of a mutant of Escherichia coli with a temperature-sensitive valyl ribonucleic acid synthetase. J. Bacteriol. 92:1076-1082. 1966.-To test our conclusion that Escherichia coli mutant I-9 possesses a valyl soluble ribonucleic acid (sRNA) synthetase that functions in vivo at 30 C but not at 37 C, measurements were made by use of the periodate method, of the level of charged valyl sRNA in this strain. A shift of temperature from 30 to 40 C resulted in a rapid discharging of valyl sRNA coordinate with the cessation of protein synthesis; at the same time, other species of sRNA, such as those for leucine, became fully charged. Identical results were obtained with a derivative of I-9 with relaxed ribonucleic acid (RNA) control. When P1 phage were grown on wild cells and then used at low multiplicities of infection to transduce temperature-resistant growth into I-9, complete cotransduction of normal valyl sRNA synthetase occurred. By means of the interrupted-mating technique, the structural gene for valyl sRNA synthetase was located on the E. coli chromosome map and found to be near thr, one-fifth of the length of the chromosome removed from the structural genes for the isoleucine-valine biosynthetic enzymes. Therefore, (i) the major valyl sRNA synthetase activity of I-9 appears to be temperature-sensitive in vivo, (ii) relaxed amino acid control over RNA synthesis does not appear to be a consequence of a normal charging of sRNA with a substitute molecule, and (iii) one structural gene for valyl sRNA synthetase is located on the E. coli chromosome not closely linked to the cistrons for the valine-biosynthetic enzymes.
D000596:Amino Acids / Q000494:pharmacology; D001426:Bacterial Proteins / Q000096:biosynthesis; D002247:Carbon Isotopes; D002874:Chromosome Mapping; D003090:Coliphages; D004926:Escherichia coli / Q000201:enzymology*; D005796:Genes; D008025:Ligases / Q000378:metabolism*; D009154:Mutation; D012329:RNA, Bacterial / Q000096:biosynthesis; D012343:RNA, Transfer / Q000096:biosynthesis; D013696:Temperature; D014498:Uracil / Q000378:metabolism
D000596:Amino Acids; D001426:Bacterial Proteins; D002247:Carbon Isotopes; D012329:RNA, Bacterial; D014498:Uracil; D012343:RNA, Transfer; D008025:Ligases